eaton



. Z-Sheets-Sheet 1.

' CPS, EATON; I Electric Call for Telophones.

No. 228,047. Patented May 25,1880.

2Sheets-Sheet 2. O. S. EATON. ElectrioGall forT'elophones,

No. 228,047; I Patented May 25,1880.

UNITED STATES PATENT OFFICE.

CHARLES S. EATON, OF LOWELL, MASSACHUSETTS, ASSIGNOR TO HIMSELF, CYRUS C. PICKERING, EDWIN LAMSON, AND EARL A. THISSELL, OF

SAME PLACE. I

ELECTRIC CALL FOR TELEPHONES.

SPECIFICATION forming part of Letters Patent No. 228,047, dated May 25, 1880.

Application filed January 3, 1880.

To all whom it may concern: pallets c d, which engage with the teeth of Be it known that I, CHARLES S. EATON, of 'the escapement-wheel e, is provided with a Lowell, in the county of Middlesex and State rod or wire, f, which isattached to its under of Massachusetts, have invented certain Imside, and is vibrated by an arm, 9, projecting 5 provements in Electric Call or Signaling Apup from the armature h of an electro-magnet,

paratus for Telephones, Telegraphs, &c., of D, the upper end of the arm gpassing through which the following is a full, clear, and exact a loop at the lower end of the rod f.

description, referencebeing had to the accom- The electro-magnet D is secured upon a suitpanying drawings, making part of this speciable shelf within the casing A, and has its 10 tication, in which-- coils connected with the main-line wire by the Figure 1 is a front elevation of myimproved wires *6 70, so that it can be operated from any call or signaling apparatus. Fig. 2 is a front of the stations within the circuit in which the elevation of the same, the dial and a portion instruments are placed, including its own staof the casing being removed to show the in tion, by means of a suitable key, E, at each I 5 terior construction. Fig. 3 is a vertical secstation, tocause the armature h to be vibrated tion through the same on the line 00 at of Fig. in the usual manner. Each movement of the i 1; Fig. 4, detail enlarged. armature h in either direction causes or allows Whereanumber of telephones are included the escapement-wheel c to rotate a distance within a single electrical circuit, as heretoequal to half that between two of its contigu- 2o fore, and the operator at one station wishes ous teeth, and by the employment of a deadto communicate with another station, he sounds beat escapement when the armature h is drawn on the electric signal or call-bell of the reaway from the magnet the pallet 07. will catch ceiving-station the number by which it is desand hold the tooth which bears against it and ignated to call the attention of the attendant prevent the escapement-wheel from again mov- 2 5 at that station. As, however, the signal-bells ing until the rod f is vibrated in the opposite of all the stations are in the same circuit, the direction by the attraction of the armature to signal is sounded simultaneously at every stathe magnet, and thus as the electro-magnetD tion, which is found to be a great annoyance is operated the escapement-wheel e is causedon account of the frequent ringing of the bells or allowed to revolve intermittingly, for a pur- 0 and the necessity of the attendant at each pose to be hereinafter described.

station being constantly on the alert in order To the outer end of the arbor m of the cs to distinguish the different signals and recogcapementwheel e is secured an index-hand or nize that of his station, so as to know when it pointer, G, which moves over a dial, H, bearis called. ing on its face thenumbers of the telephone- 3 5 To avoid this simultaneous ringingof allof stations in the circuit and certain other numthe signal-bells of the different stations and hers to be referred to hereinafter, the numto cause only the bell at the particular stabers on the dial corresponding to the number tion to which the message is to be sent to be of teeth of the escapement-wheel e-that is, sounded, whileall the others remain silent, is one tooth for each number on the dial. Upon 4.0 the object of my invention, which consists in the arbor m is also secured a wheel or disk, I,

certain novel devices for effecting the deprovided with a notch, 12, and against the pe- 9o sired result, as will be hereinafter fully set riphery of the disk I rests one end, 16, of a forth. nearly-balanced lever, K, having its fulcrum In the said drawings, A represents a casatq, the opposite end 17 of this'lever being 5 ing, within which is secured the frame B of a so placed as to come into contact with a metrain of clock-work, C, which is' actuated bya tallic stud or post, L, when its end 16 is al- 5 a; spring, a, and'is provided'with a dead-beat lowed to drop to, or nearly to, the bottom of escapement. the notch 1) in the disk I, this contact of the The plate b, which carries'at its ends the end 17 of the lever K with the stud L comaasgoaa I pleting a local circuit, in which the call-bell M is included, and giving an alarm to notify the attendant that it is desired to communicate with hisstation.

The notch p of the disk I is so placed with respect to the index-hand G and dial H that the end 16 of the lever K will drop into it to close the bell-circuit and give the alarm only when the index-hand points to a particular part of the dial corresponding to the number of the station to which the instrument belongs; and to close the bell-circuit when the hand is in the position referred to, the operator at the transmitting-station must keep the key E depressed a sufficient length of time to give the end 16 of the lever time to drop to, or nearly to, the bottom of the notch 19, so that its opposite end 17 will strike the stud L; otherwise the call-bell will not be rung. When, however, the operator removes his finger from the key E, allowing it to rise, the circuit through the electro-magnet D is closed, and the disk I is rotated sufficiently to raise the end 16 of the lever K out, or nearly out, of the notch 19, and thus open the bell-circuit and stop theringin g of the call-bell M.

\Vhen the notch 19 of the disk I is carried rapidly past the end 16 of the lever K, which is effected by releasing the key E instantaneously after each depression, the end 16 will not have time to drop into the notch p sufiiciently far to bring the other end, 17, of the lever into contact with the stud L, but will be caught by the inclined portion 18 of the notch 19 and again raised up before the end 17 can come into contact with the stud, and consequently the call-bell M will not be sounded. This rapid movement of the notch 19 of the disk I past the end 16 of the lever K will occur when some other station in the circuit is bein called, which will necessitate the revolving of the notch 19 past the end 16 of the lever; and thus it will be seen that only the call-bell at the particular station with which it is desired-to communicate is rung, while all the other bells in the circuit will remain silent, whereby the annoyance caused by the frequent ringing of the bells is avoided and no attention is needed on the part of the operator at any station until he hears his call bell or alarm sounded, when he knows that a communication with him is desired.

The escapement-wheels c of the several in struments in the circuit all revolve in unison, together with the index-hands, which are all set to point simultaneously to the same numher on their respective dials, and when the operator at any station wishes to communicate with another station in the same circuit-for instance, No. 6he manipulates the key E (taking care to release it instantaneously after each depression) until the index-hand G points to number 6 on the dial, at which time the key will be up. He then again depresses the key, this time holding it down with his finger, which moves the index-hand to a point midway between 6 and 7 and brings the notch 19 of the disk I of the instrument at the receiving-station under the end 16 of the lever K, which will then drop therein, owing to the arbor m remaining stationary by reason of the continued depression of the key E at the transmitting-station, which causes the call-bell at station 6 to ring the alarm in the manner previously described, this ringing continuing as long as the operator at the transmitting-station keeps his key E depressed. As soon, however, as he thinks a sufficient alarm has been sounded he removes his finger from the key E, which produces a movement of the arbor m and causes the end 16 of the lever K of the receiving-station to be raised out or partly out of the notch 17, thus opening the bell-circuit and stopping the alarm.

The operator at the transmitting-station then, by means of his key E, moves the indexhands G of the several instruments in the circuit round to a predetermined number on the dials which has no station-assigned to it--for instance, 10-so that when the hand points to this number it will indicate to all the other stations that the line is in use. The operator at the receiving-station then, by means of his key E, rotates the index-hands Gr round to another unassigned nu m berforinstance, 15 and then opens or breaks the electric circuit in which the eleetro-magnets D are placed (as is necessary in using a Bell telephone) by means of a suitable switch, 'N, or by depressing the key E and retaining it in that position, which will cause the hands G to move half-way to the next numberin this case 1 and when the operator at the transmittingstation sees the hand pointing between 15 and the next number in advance, 1, he knows that the circuit is open and that the operator at the receiving-station is ready to talk.

When the conversation has been terminated the circuit is closed by both of the operators moving the switch N of their respective instruments, or allowing the key E to rise, which causes the armatures of the electro-magnets D to be attracted and the index-hands G to move from the position midway between 15 and 1 to 1, which indicates to all of the stations that the line is free and ready for use.

When, however, an operator at any station goes to his instrument and finds the hand pointing to 10 or 15 he knows that the line is in use, and must therefore wait until the hand indicates that the line is again free.

I do not confine myself to the use of the notched wheel I and lever K, as it is evident that some other device may be used in connection with the rotating arbor m, which will set the alarm mechanism in action when the arbor m is held stationary for a sufficient length of time with the hand pointing to the number or mark on the dial corresponding to its own station.

Instead of an electric call-bell, a clock-alarm mechanism may be employed, if preferred, and in lieu of employing a train of clock-work and a spring or weight in connection with an elec YIN tro-magnet, I), to rotate the arbor carrying the device for setting the alarm mechanism in action, the arbor may be rotated by a ratchetwheel and pawl or pawls, or other mechanism connected directly with the vibrating arma ture h of the electro-magnet.

Instead of attaching the index-hand G and I notched disk I to the arbor m of the escapement-wheel c, it is evident that they may be attached to some other arbor properly connected with and revolved by the train of clockwork without departing from the spirit of my invention.

What I claim as my invention, and desire to secure by Letters Patent, is-

1.111 an electric call-signal apparatus, the arbor m, provided with an index-hand, G, and caused or allowed to rotate intermittingly by the action of an electro-magnet, D,-capable of being operated from any station in the electric circuit, in combination with a dial, H, bearing the-numbers of the stations in the circuit, and a device or mechanism having a retarded movement and controlled by the arbor m, for setting in action the call-bell or alarm mechanism when the arbor is arrested and held stationary for a sufficient length of time, with the index-hand pointing to the number upon or part of the dial designating the station to which the instrument belongs, substantially as set forth.

2. In an electric call-signal apparatus, the intermittingly-rotating arbor m, provided with an index-hand, G, and a disk, I, having a notch,

35 1a, in combination with the dial H and the lever K, having a retarded movement and controlled by the arbor m, for setting in action the call-bell or alarm mechanism when the end 16 of the lever is allowed to drop down into the notch 19, substantially in the manner and for the purpose described.

3. In an electric call-signal apparatus, the clock-work G, operated by the electro-magnet D from any station in the circuit by means of a key, E, for the purpose of producing an intermittent rotation of the arbor m, in combination with the hand Gr, dial H, notched disk I, and lever K, having a retarded movement and controlled by the arbor m, or equivalent mechanism, for setting in action the call-bell or alarm mechanism, substantially as described.

4. The combination, in an electric circuit, of a series of three or more call-signal instruments, each consisting essentially of an arbor, m, rotated intermittingly, as described, and provided with a hand, G, moving over a dial, H, an electro-magnet, D, capable of being operated by means of the key E of any station in the circuit to cause or allow the arbor m to rotate, and a means for setting in action the call-bell oralarm mechanism having a retarded movement controlled by arbor m when the arbor is arrested and held stationary for a sufficient length of time, with thehand pointing to a given number or part of the dial, all constructed to operate together substantially in the manner and for the purpose set forth.

Witness my hand this 1st day of January, A. D. 1880.

CHARLES s. EATON.

In presence of- P. E. TESGHEMAGHER, W. J. OAMBarDeE. 

